This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The proposed study will evaluate the effects of a 12-week aerobic exercise program on flow mediated dilation in postmenopausal African American and Caucasian women. It will employ a 2x2 study design in which subjects will be randomized in a 2:1 ratio to either the exercise training or the no exercise training condition, respectively, within each racial group. FMD will be measured at baseline and at the conclusion of the study. The specific hypothesis is that there will be no racial differences in the improvement of FMD following an aerobic exercise training program, but there will be a lower baseline FMD in African American subjects. Secondary endpoints will evaluate the effect of this exercise training on postprandial metabolism.